trailer tire life.
Ditto on Discount tire's they are very good. They give you a walking out the door price.
Most of what's been posted in this thread is anecdotal or conjecture, if it were me, I think I'd be inclined to suck it up and replace trailer tires based on the time cycle referenced by Discount Tire.
FWIW, Discount Tire has proven to me and a handful of friends to be straight-shooters, and they provide great customer service and great value.